Method of and apparatus for removing slag from center hole of ingot soaking pits



June 23, 1953 F. DRACKLEY METHOD OF AND APPARATUS FOR REMOVING SLAG FROM CENTER HOLE oF INGOT soAKING PITs 1947 3 Sheets-Sheet l Filed March 27,

f f/f 0 l///,5////// June 23, 1953 F DRACKLEY 2,643,203

METHOD 0F AND APPARATUS FOR REMOVING SLAG FROM CENTER HOLE OF INGOT SOAKING PITS Filed March 27, 1947 3 Sheets-Sheet 2 June 23, 1953 F. DRACKLEY 2,543,203

METHOD OF AND APPARATUS O G SLAG ROM CENTER HOLE OF' ING AK PITS 3 Sheets-Sheet 5 F Filed March 27, 1.947

Patented June 23, 1953 METHOD OF AND APPARATUS FOR REMOV- ING SLAG FROM CENTER HOLE OF INGOT SOAKING PITS Frank Drackley, Whiting, Ind., assignor to Inland Steel Company, a corporation of Delaware Application March 27, 1947, Serial No. 737,700

8 Claims. l

This invention relates to a method of and apparatus for removing collected slag from the center hole of an ingot soaking pit, and more particularly it relates to an apparatus which may be used with a soaking pit crane and ingot tongs for reaming or grinding out such slag.

In the processing of ingots in a blooming mill they must be soaked at high temperature for a considerable period of time. This is done in a soaking pit which is merely a sand or re brick lined pit about ten or twelve feet deep, with hot gas inlets in its side wall near the floor and a hot gas `outlet in the center of the floor. It is set in the licor of a pit room, and is provided with a cast iron cover.

The ingots are soaked by preparing a layer of coke braize on the floor of the soaking pit, standing the ingots on end on the coke braize bottom and bringing the ingots to the desired temperature by admitting highly heated gases to the pit from a plurality of outlets which are spaced about the side wall and tangential thereto. The hot gases whirl around the wall of the pit, into the center, and are drawn through the center hole and out into an underground-flue by a forced draft system. This waste hot gas is then used to heat Waste heat boilers.

The temperature in the soaking pit is high enough to produce semi-molten oinder and slag which flows into the center hole and solidies on the side Walls thereof, due to the, relatively low temperature of the walls. Thus, a center hole which is normally 36 inches in diameter may choke with slag until its diameter is reduced to as little as 18 or 20 inches. The inevitable result of this slag formation is reduced efficiency in pit heating, loss of Waste heat for the operation of the waste heat boilers, and the production of undesirable high pressure in the pit which causes hot gases to leak out at the margin of the pit cover and burn out the castings.

Heretofore there have been three principal methods used for removing the slag from the center hole of a soaking pit. One method was to bolt a long chisel shaped billet of iron to one of the tongs of a pit crane to serve as a ram. This job required the service of two or three millwrights. The crane man would then center the pit crane over the center hole of the pit and drop the ram onto the accumulated slag in an attempt to break the slag deposit from the side of the center hole and into the horizontal flue beneath.

Another practice was to bolt a large billet to the pit crane ram and whirl it around in the hole by using the tong twister drive on the pit crane. Each of these practices resulted in very high maintenance costs on both cranes and pits, as well as lost time for crane and pit repair. The rst named method frequently caused the pit crane counterweight cables to jump from theiry sheaves due to slack in the cables when the billet hit the slag.

A hand method of cleaning the center hole was also used, which consisted of inserting a long chisel bar through a small hole in the top of the pit cover, and driving it into the slag with a sledge hammer. This, of course, was extremely slow and heavy work, and did not produce very satisfactory results.

The method of the present invention involves suspending a dead weight element on the ingot crane tongs to prevent slack in the cables, hanging a heavy cutting element from the jaws of the tongs in such a. manner that it is free to move vertically with respect to the tongs, lowering the cutting element onto the top of the slag, and revolving the end of the crane arm in a small circular path so as to permit the cutting element to ream or grind the slag from the wall of the center hole.

The apparatus by which the method is carried out consists of a reamer which may be handled by the ingot tongs of a pit crane and used by the crane man. It consists generally of a long square shaft which is provided at its upper end with a carrying member which is adapted to receive the pit crane ingot tongs, and which has a stop at its lower end. Slidably mounted on the shaft is a heavy reamer head which has a plurality of cutting blades disposed about its lower end, the reamer head being of a slightly smaller diameter than is the center hole. A stop member near the upper end of the shaft is of larger diameter than the center hole, so as to limit the downward travel of the reamer.

The device is picked up with the pit crane ingot tongs and lowered into the center hole until the reamer head is resting on the slag. `The crane man then rotates the end of the crane arm in a small circular path so as to permit the cutting element to grind the slag from the wall of the center hole. The cutter head is carried down into the slag by its own weight.

The invention eliminates the high maintenance cost and loss of time caused by the earlier methods of removing slag by using a ram or a whirling billet, and does a faster and more thorough job. It is likewise infinitely superior to the old hand operation.

The invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a central section through an ingot soaking pit showing the apparatus in use, the carrying member of the reamer being shown partially in section; Fig. 2 is a partial section taken as indicated at 2-2 of Fig. 1; Fig. 3 is a side elevation of the reamer; Fig. 4 is a top plan thereof; Fig. 5 is a bottom plan thereof; Fig. 6 is a section taken as indicated at 6-6 of Fig. 3; Fig. 7 is a section taken as indicated at 'iof Fig. 6; and Fig. Sis a section taken as indicated at 3 8 of Fig. 6.

Referring to the drawings in greater detail, I is an ingot soaking pit which has in its side wall hot gas inlets II, and at its bottom a center hole I2 which leads to a ue I3. The center hole is shown with a substantial accumulation of slag I4 on its side walls.

An ingot tongs I5 is carried by a crane (not shown), and from the tongs I5 is suspended the center hole reamer, indicated generally at It.

The reamer consists of a square shaft Il which is provided at its lower end with a stop member I8, and at its upper end with a carrying member, indicated generally at I9.

The carrying member I9 includes a pair oi heavy blocks and 2| secured to opposite sides of the shaft I'I, the blocks being provided with a pair of opposed orifices 22 and 23, to accommodate the jaws of the tongs. Above the blocks 20 and 2| are a pair of bifurcated wing members 24 and 25. The arms of the ingot tongs iit into the bifurcations and are thereby prevented from twisting.

Slidably mounted on the shaft I1 is a cutting element which consists of a heavy reamer head 26; said head preferably weighing in the vicinity of 3000 pounds and being of a diameter slightly less than that of the center hole. For example, a inch reamer head is preferred for use in a 36 inch center hole. The lower end of the reamer head has a frusto-conical surface 21 to which are afiixed a plurality of radially disposed blades 23. For ease of construction, the reamer head 25 may be formed from a plurality of six inch billets which are welded together. The cutting blades 28` are preferably coated with Stellite in order to withstand the abrasion and heat which are encountered in use.

Near the upper end of the shaft II is a slide travel stop 29 which is of somewhat larger diameter than the center hole of the soaking pit so that it serves both to limit the upward travel of the reamer head 2G, and the downward travel of the entire reamer i6. The slide travel stop 29 is provided with a plurality of openings 3S in order to permit the crane man to observe the progress `of the work; and it is strengthened by a plurality of braces 3| which are welded at their upper ends to a brace block 32.

In operation, the reamer is picked up by engaging the ingot tongs in the orifices 22 and '23, and is lowered into the center hole of the soaking pit until the blades 28 rest upon the top of the accumulated slag. The combined weight of the shaft Il and carrying member I9 serves as a dead weight element which prevents the crane cables from jumping their sheaves when the reamer is being used. The crane man then revolves the end of the crane arm in a circle o small diameter so as to drive the cutting blades 28 of the reamer head 25 into the slag and thus remove it from the wall of the center hole by a reaming, or grinding action. The reamer head 25 is driven downwardly through the accumulated slag only by its own weight.

The length of the shaft I1 below the stop 29 is sufficient to permit the reamer head to drive completely through the center hole, and the stop 29 contacting the rim of the center hole prevents the cutting blades from coming in contact with the bottom of the nue I3.

The foregoing detailed description is given for clearness of understanding only, and no unneccessary limitations should be understood therefrom, for some modifications will be obvious to those skilled in the art.

I claim:

1. The method of removing slag from the center hole of an ingot soaking pit which comprises securing a heavy cutting head adjacent the lower end of a dead weight element in such a manner that it is capable of only limited vertical motion with respect to the dead weight element, picking up the dead weight element and cutting head with a crane ingot tongs, lowering the tongs toward the center hole of the soaking pit until the cutting head is resting on the slag, and moving the end of the crane arm in a small circular path so as to permit the cutting element to grind the slag from the wall of the center hole.

2. A center hole reamer for an ingot soaking pit, comprising a shaft having a stop at its lower end, a heavy reamer head slidably mounted on said shaft, means for preventing rotation of said head on said shaft, said reamer head having a substantially frusto-conical surface at its lower end, a plurality of radially disposed cutting blades on said surface, a slide travel stop for the reamer head adjacent the upper end of the shaft, said stop being of larger diameter than the hole to be reamed so as to limit the downward travel of the reamer, and a carrying member at the upper end of the shaft, said carrying member having a pair of oppositely disposed orices to accommodate the jaws of an ingot crane tongs and a pair of bifurcated wing members in register above said orifices and adapted to engage said jaws to prevent twisting of the reamer in the tongs.

3. Apparatus for removing slag from the center hole of an ingot soaking pit, comprising, a dead weight element provided with means by which it may be carried by a crane, said element being adapted to maintain a predetermined minimum load on the crane cables, said dead weight element including an upright shaft, a heavy reamer head slidably mounted on said upright shaft, means for preventing rotation of said reamer head with respect to the shaft, and cutting means adjacent the lower end of said reamer head.

4. A center hole reamer for ingot soaking pits, comprising, a shaft having a stop at its lower end, a heavy reamer head slidably mounted on said shaft, means for preventing rotation of said head on said shaft, cutting means adjacent the lower end of said reamer head, a carrying member, means on said carrying member adapted for engagement by an ingot crane tongs, and means on said member for preventing twisting of the reamer in the tongs.

5. A device of the character described in claim 4 wherein the reamer head has smooth upright sidewalls and a substantially frusto-conical surface at its lower end, and the cutting means consists of a plurality of radially disposed blades on said surface.

6. A device of the character described in claim References Cited in the le of this patent UNITED STATES PATENTS Name Date Taussig Mar. 4, 1902 Number Number 10 Number Name Date Ord. Jari. 22, 1907 Renner Nov. 11, 1924 Small Aug. 30, 1927 McCoy Feb. 10, 1942 Hunter et al Feb. 12, 1946 Christensen May 23, 1950 FOREIGN PATENTS Country Date Great Britain of 1911 Great Britain Oct. 16, 1922 France Apr. 29, 1931 

3. APPARATUS FOR REMOVING SLAG FROM THE CENTER HOLE OF AN INGOT SOAKING PIT, COMPRISING, A DEAD WEIGHT ELEMENT PROVIDED WITH MEANS BY WHICH IT MAY BE CARRIED BY A CRANE, SAID ELEMENT BEING ADAPTED TO MAINTAIN A PREDETERMINED MINIMUM LOAD ON THE CRANE CABLES, SAID DEAD WEIGHT ELEMENT INCLUDING AN UPRIGHT SHAFT, A HEAVY REAMER HEAD SLIDABLY MOUNTED ON SAID UPRIGHT SHAFT, MEANS FOR PREVENTING ROTATION OF SAID REAMER HEAD WITH RESPECT TO THE SHAFT, AND CUTTING MEANS ADJACENT THE LOWER END OF SAID REAMER HEAD. 